Brown the oxtail in the olive oil in a frying pan, and transfer the pieces to a flameproof casserole. Peel and slice the onion, and lightly brown it too, before transferring to the casserole. Tuck in the bay leaves. Pour the red wine into the frying pan, and bring to the boil, scraping up any caramelized cooking juices stuck to the bottom of the pan. Pour over the oxtail.
Add enough stock or water to come about three-quarters of the way to covering the meat. Simmer on the hob or cook in a very low oven for 2 to 3 hours until the meat is tender.
Strain the cooking juices into a bowl. Cool, and then refrigerate until next day, when you can lift off the layer of fat.
When the meat is cool enough to handle, remove all the bones, put the meat in a container, cover, and refrigerate until next day.
When ready to make the tart, peel and thinly slice the potatoes. Blanch them for 30 seconds or so in boiling water, and then drain and rinse under the cold tap. Lay the slices on a clean tea towel to dry.
Chop the prunes, and mix them with the meat and a few spoonfuls of the by now jellied cooking juices.
Line with greaseproof paper and thickly butter a cake tin about
Put the meat mixture in the potato-lined tin, make it level, and fold over the potatoes at the edge. Cover with another neatly overlapping layer of potatoes. Season the top. Butter the surface, and cover loosely with a sheet of foil or greaseproof. Bake in a preheated oven at about 190°C/375°F/gas mark 5 for 45 to 50 minutes, until the potatoes are cooked through and nicely browned.
Before turning out onto a plate, weight the tart down for 15 minutes or so to firm it up and make cutting a little easier. With a sharp knife, cut into wedges, and serve. I like to serve this with a purée of swede and garlic, lightly flavoured with clove or cardamom, or creamed cabbage flavoured with nutmeg.
© 2000 Frances Bissell. All rights reserved.